In this paper, we have used the basic U-Net neural network to learn degradations in document images.
More complicated neural networks can be adopted in future work, such as the ResNet [1]} and DenseNet [2]} and DSN used in [3]}.
In addition, the networks in different iterations can also be different.
The complicated neural network can be applied in the beginning iterations and light neural network can be used in the end iterations for fine-tunning.
